Automatic or semi-automatic multi1 spindle grinder for diesel engine fuel nozzles



March4, 1969 G. GABRIELL! 3,430,388

AUTOMATIC 0R SEMI-AUTOMATIC MULTI-SPINDLE GRINDER FOR DIESEL ENGINE FUEL NOZZLES Sheet of 5 Filed Feb. 8, 1966 F7 Z Zf /l/ s 1 1 March 4; 1969 G. GABRIELLI 3,430,388

AUTOMATIC OR SEMI-AUTOMATIC MULTI-SPINDLE GRINDER FOR DIESEL ENGINE FUEL NOZZLES Filed Feb; 8,- 1966 Sheet 2 of 5 March 4. 1969 5, GABRlELL; 3,430,388

AUTOMATIC 0R SEMI-AUTOMATIC MULTI-SPINDLE GRINDER FOR DIESEL ENGINE FUEL NOZZLES Filed Feb. 2, 1966 Sheet 3 -of 5 United States Patent 3,430,388 AUTOMATIC 0R SEMI-AUTOMATIC MULTI- SPINDLE GRINDER FOR DIESEL ENGINE FUEL NOZZLES Gilberta Gabrielli, 83/85, Via Ferrarese, Bologna, Italy Filed Feb. 8, 1966, Ser. No. 525,979 Claims priority, application Italy, Feb. 11, 1965, 3,268/65; Apr. 22, 1965, 9,396/ 65 US. Cl. 51-3 Int. Cl. B24b 5/12 7 Claims ABSTRACT OF THE DISCLOSURE The invention relates to an automatic or semi-automatic multi-spindle grinder for diesel engine fuel nozzles.

It is known that in the manufacture of diesel engine fuel nozzles it is necessary to grind the rear flat surface, the interior of the cylindrical needle guide surface and the interior of the conical needle seat. For this purpose multi-spindle grinders are known which grind only the interior or the cylindrical needle guide surface and the interior of the conical seat of said needle valve. On the contrary, the grinding of the rear flat end surface of the nozzle must be ground upon a separate grinding machine so that, presently, for the complete grinding of fuel nozzles it was necessary to employ two separate grinders, which entailed a double chucking and removal of the piece and considerable time losses.

The invention aims first to overcome these drawbacks by providing an automatic or semi-automatic multispindle grinding machine for diesel engine fuel nozzles which comprises a stepwise rotatable supporting member provided with at least three workpiece spindles and advancing stepwise so as to cause said spindles to pass through three subsequent working stations (in correspondence of each of which a grinder is arranged viz.) in correspondence of one of said working stations an external grinder device is mounted for flattening the end of the nozzles; in correspondence of another station an internal grinder device is provided for grinding the conical needle seat of the nozzle and a third grinder for the internal grinding of the cylindrical needle-guiding surface, in correspondence of a third station.

By this embodiment of nozzle grinder, each fuel nozzle, after it has been chucked to a single working spindle, is subjected, in a single working cycle of the grinder, i.e. by passing twice through three working stations, to a complete grinding both of the cylindrical and conical internal surfaces and of the outer flat surface.

It is also possible to provide a four-spindle supporting member, eifecting a four-step cycle, three stations being employed for the working of the pieces and the fourth station for the removal of the finished nozzles and the mounting of a new nozzle to be ground.

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However the preferred embodiment of the invention, is such that at the working station at which the flattening of one of the nozzle ends is effected, also the removal of the finished nozzles and the chucking of the nozzles to be ground are effected. For this purpose, the flat end grinding wheel is mounted so as to be withdrawn from a working position to a rest position, clear of the nozzles.

This particularly simple embodiment of the invention is rendered possible by the fact that the flat end grinding requires less time than the grinding of the internal cylindrical and conical surfaces.

The supporting member for the workpiece spindles may be in form of a drum which is provided with three axially parallel chuck members arranged in a circle at interval from one another and projecting from the front end of the spindle drum. In this embodiment, the two internal grinders and the outer flat grinder are arranged in front of this end of said drum, which is mounted on a supporting member which is rotatably mounted parallel to the spindle axes and is slidably mounted for movement away and towards the grinding devices. In this case the dressing devices of the two internal grinders are mounted for transverse displacement relative to the axis of the spindle drum, while the dressing means of the external fiat grinder is mounted so as to operate when said grinder is in withdrawn position.

A method which is particularly adapted for the operation of said three-spindle diesel fuel nozzle grinder consists in advancing and then withdrawing the spindle drum supporting means twice during each working cycle of the machine. By this arrangement and method of operation, after the first advancing movement of the drum, the rough grinding of the internal surfaces and the complete grinding of the nozzle end are etfected, and afterwards, after the first withdrawal of the drum supporting means, the grinding pins of the internal surfaces of the nozzles are dressed while the flat-grinding wheel is removed from its working position to its rest or sizing position. Thereafter, after the second advancing movement of the drum-supporting member the fine grinding of the inside surface is effected While in correspondence of the station where the flat grinder is mounted, the finished nozzle is removed and a new nozzle is mounted. After the second withdrawal of the said drum, said drum is advanced by a further step and the front surface grinder is driven to working position.

Further characteristic features and advantages will be apparent from the following specification of a preferred embodiment of the invention, which has been shown by way of example in the accompanying drawings, in which:

FIGURE 1 shows in an exploded perspective view the essential parts of a three-spindle diesel fuel nozzle-grind ing machine;

FIGURES 2, 3 and 4 show in axial section through said nozzles the single end grinding and the two internal grinding operations which are effected successively on a nozzle;

FIGURE 5 shows a variation of the end-grinding operation of a nozzle;

FIGURES 6 and 7 show in front view the three grinding devices of the machine in dressing and in working posi tion, respectively;

FIGURE 8 is a view of the internal grinder of the hollow cylindrical nozzle surface;

FIGURES 9 and show in plan view and in rear elevation the internal grinder of the nozzle valve seat.

FIGURE 11 shows diagrammatically in plan view another embodiment of a multispindle grinder.

In the manufacture of diesel nozzles, such as that shown by way of example in FIGURES 2 through 5, the following grinding operations must be effected: Outside upon the flat rear nozzle end 2, and inside within the cylindrical bore 5, serving as needle valve guide and Within the conical valve seat 4 at the nozzle end.

This triple grinding of the said three nozzle surfaces may be effected according to the invention simultaneously on three different nozzles by employing the automatic or semi-automatic multi-spindle grinding machine as diagram matically shown in FIGURE 1. This machine comprises a substantially horizontal drum 6 which carried the three workpiece spindles 7 which project parallel to each other with their workpiece chucking ends beyond the front drum end and are rotated by an electric motor mounted within the same drum, which carries also the control devices of the workpiece-chucking means. The spindle 7 are arranged on drum 8 in a circle at 120 intervals.

Drum 6 is rotatably mounted in a supporting member 8 which is slidably mounted for movement in both directions upon horizontal guide members 10 fastened to the machine frame 9. The reciprocation of the drum-supporting member 8 may be controlled by means of acam groove formed in a cylindrical piece 11 and in which a cam roller 12 mounted upon the drum supporting member 8 is engaged. Thus by rotation of piece 11, the supporting memher 8 is driven in reciprocation.

Drum 6 is driven stepwise in its supporting member 8 in the direction of arrow 13, so that each spindle 7 accomplishes a complete revolution during a complete machine cycle, by passing through three working stations I, II and IH, in each of which it stops for a predetermined time. The stepwise movement is effected by driving 9. Geneva wheel 14 by a pawl 16. On the shaft of wheel 4 is a long cylindrical gear which meshes with a gear 19 which in turn meshes with gear 18 fastened to drum shaft 17, the arrangement being such as to permit a reciprocation of drum 6, while gears 18, 19 and 20 are always in mesh.

Facing the front end of drum 6, are three grinding devices or grinders S1, S2, S3 each mounted to correspond with a working station I, II or III, respectively. The grinder S1 in front of station I is a flat surface grinder for the end surface 2 of nozzles 1. The grinding wheel of grinder 1 may be either disc-shaped, as shown at 21, FIG. 1 or cup-shaped, as shown at 121, FIG. 5. Grinding wheel 21 or 121, together with their motor and gear unit 24 are mounted upon cross slides 25, 26. Lower slide 26 is slidable upon substantially horizontal guides 27 fastened to the machine frame 9. Upper slide 25, upon which the grinding wheel and the corresponding driving means 24 are mounted is slidable upon lower slide 26 parallel to the axes of workpiece spindles 7. The sliding of slides 25, 26 may be controlled by suitable means, such as hydraulic cylinders 28 and 29.

By shifting the lower slide 26, the grinding wheel of the flat grinder S1 may be brought into a working position, in the direction of the drum axis, as shown in FIGURE 7 and into a dressing position, as shown in FIGURE 6, in which the grinding wheel is shifted sidewise outwardly. When the grinder S1 is in working position, the flat end 2 of the nozzles is ground. Said nozzles are carried by spindle 7 in working station I.

When on the contrary, the grinding wheel is shifted sidewise outwardly, it can be brought into contact with a dressing device 30 mounted on said machine frame, as shown in FIGURE 6. The movement of grinding wheel 21 or 121 in the direction of the workpiece is effected by shifting upper slide 25 parallel to the axis of spindle 7.

The grinding device S2 arranged in correspondence of the working station 11 serves for grinding the conical needle valve seat 4 of the diesel nozzle 1 and is provided with a tapered grinding pin 22 which lies substantially co-axially to spindle 7 at station II and to nozzle 1 chucked thereon. Grinding pin 22 is mounted together with its m0- tor and gear unit 31 upon a horizontal disc 32 which is mounted so as to be angularly shiftable upon an upper intermediate disc 33 to which it is adjustably fastened by means of fastening screws 133 passed through slots 34 in the form of arcs of circle, as particularly shown in FIG- URES 9 and 10. The upper intermediate disc 33 is slidably mounted upon a guide member formed upon a lower intermediate disc 35 which is fastened by means of screws 36 passed through arc-shaped slots upon a bottom disc 37 the whole being so arranged as to permit limited angular movements. Disc 37 is provided with a dovetail key member 137 slidable in a dovetail slot 38 provided in the machine frame member 9. Guide member 135 extends parallel to the axis of grinding pin 22 and to the axis of the conical needle valve 4 of nozzle 1 fastened onto spindle 7 at working station II. The feed movement of grinding pin 22 during the grinding of needle valve seat 4 of nozzle 1 is effected by shifting the grinding unit 22, 31 together with discs 32, 33 upon slide guide 135 of the lower intermediate disc 35. Slide guide 137, 38 upon frame 9 is directed, on the contrary, parallel to the axis of grinding pin 22.

The shifting of grinding unit 22, 31 together with all discs 32, 33, 35 and 37 upon slide guide 38 of frame 9 serves for bringing grinding pin 22 to an operative grinding position.

The shifting upon guides 135 and 38, respectively, may be controlled by any suitable conventional means such as hydraulic cylinders, cam control devices or the like.

The grinding device S3 at station III serves for grinding the cylindrical needle valve guide 3 of nozzle 1, and is provided with a cylindrical grinding pin 23 mounted coaxially of spindle 7 at station III and of nozzle 1 chucked thereon. Grinding pin 23 is provided with a driving unit 39 and is mounted together therewith for slidable movement in a transverse slide 40, as shown particularly in FIGURES l and 8. Slide 40 is slidable in a slide guide 41 fastened to the machine frame 9 and directed perpendicularly to the hollow cylindrical needle valve guide 3 0f nozzle 1.

The shifting of the grinding unit 23, 39 upon the transverse slide 40, parallel to the axis of said unit serves as a feed movement for the grinding pin 23, when the same is dressed and/ or during the working of the hollow cylindrical guide 3 of the needle valve of nozzle 1. The shifting of the transverse slide 40 upon the slide guide 41 provides on the contrary the feed movement of the grinding pin 23 during the grinding of said hollow cylindrical guide 3.

Also in this case, the control of the sliding movements of grinding unit 23, 39 upon transverse slide 40 and of the said slide 40 upon slide guide 41 can be performed by means of any suitable conventional control and driving means. In the embodiment as shown, the rear end of the grinding unit 39 is engaged by the upper arm of a double-arm swinging lever 42 pivotally mounted at 142 upon transverse slide 40. The lower arm of lever 42 is provided with a longitudinal slot 43 in which is engaged the crank pin of crank disc 44, which, by revolving of said pin causes the swinging of lever 42 and the axially parallel shifting of grinding unit 53 upon slide 40. Slide guide 41 of transverse slide 40 is inclined with respect to the horizontal plane so as to remain substantially parallel to the connecting line between the axes of the workpiece spindles lying at stations I and III respectively. In the example as shown, the inclination of slide guide 41 amounts to about 60. Thus slide 40 tends to slide downwardly by gravity along guide 41 and to push by means of push rod 45 an arm of a swinging angle lever 46, as particularly shown in FIGURE 8. The other arm of said lever 46 bears against a cam disc 47. Thus by rotating said cam disc 47, slide 40 is either shifted upwardly along slide 41 by cam action, or slides downwardly by gravity. In this manner a reliable forward and rearward movement of grinding pin 23 is attained.

The internal grinding devices S2, S3 are provided with dressing devices 49, 50, which are arranged below the corresponding grinding pins 22, 23 upon a common sup porting member 51 which can be lifted and lowered by means of a hydraulic piston rod 52, as particularly shown in FIGURES 6 and 7. Thus the dressing devices 49, 50 may be either lifted to the working position as shown in FIGURE 6, in which they act on the side of the corresponding grinding pins 22, 23, or can be lowered to the rest position, as shown in FIGURE 7, in which they leave the space free between the internal grinding devices S2, S3 and the workpiece spindle-carrying drum 6.

The operation of the above-described three-spindle grinding machine is as follows:

Each nozzle 1 to be ground is chucked to the corresponding spindle 7 at station I, where the fiat end grinding is effected and, after this first grinding, by stepwise advancing through stations II and III, is returned to station I, where the completely ground nozzle is removed and replaced by a new nozzle.

By further advancing by one step, drum 6 is revolved so as to bring said nozzle 1 from station I to station H, where the conical internal valve seat is ground, after which the drum 6 is further revolved by one step and nozzle 1 is brought to station III, where the cylindrical bore 3 is ground, while at the same time, other nozzles are brought to station H and I. The stay times at said three stations are the same.

During each operation of the machine, viz. between two subsequent advancing steps of drum 6, the drumsupporting member 8 is advanced twice in its working position against the grinding devices S1, S2 and S3, and then it is again withdrawn. By the first advancing of said supporting member 8, the flat-grinding unit 21, 24 comes to its working position, while dressing devices 49, 50 of the internal grinders S2, S3 are lowered in their rest position. In said advanced working position of supporting member 8, the grinding pins 22, 23 engage the corresponding internal walls of nozzles 1 at stations II and III, while the grinding wheel 21 or 121 of flattening grinder S1 works against the end of nozzle 1 at station I. During this step, the first or rough internal grinding of nozzles 1 at stations H and III and the complete end grinding of nozzle at station I is effected.

The drum supporting member 8 is then withdrawn to its starting position. Subsequently the fiat grinding unit 21, 24 is removed to its rearward sidewise dressing position while the dressers 49, 50 are lifted and shifted against the grinding pins 22, 23 of S2, S3 (FIG. 6), so as to dress said pins. Also the grinding wheel 21 or 121 places itself against the corresponding dresser 30 and may be dressed, although this operation is not necessary at each working cycle, but may be performed after a suitable number of cycles, as desired.

Subsequently the dressers 49, 50 are again lowered and the drum-supporting member 8 is again shifted towards the grinders S1, S2, S3. In this working step, the grinding pins 22 and 23 at stations H and III are advanced so as to finish-grind the internal surfaces of the corresponding nozzles 1, while the grinding wheel unit 21, 24 is maintained in its sidewise dressing position as shown in FIGURE 6, and in the meanwhile the freely accessible completely ground nozzle 1 at station I may be removed and replaced to a new one. This operation can be eflfected by hand or automatically, by employing conventional means.

After the finish grinding of the inside surfaces 3 and 4 and the chucking of a new nozzle at station I, the drumsupporting member 8 is again withdrawn to its starting position, then drum 6 is revolved by one step and the flat grinding unit 21, 24 is again advanced to working position and thus the two-step cycle of the machine may be again started.

-By the described method of operation of the machine, in the working station I, in the first working step of each cycle, viz. after the first advancement of the supporting member 8, the grinding unit 21, 24 is advanced and flat-grinds the nozzle end 2.

In the second working step of the same cycle, viz. after the second advancing of member 8, the finish-ground nozzle is replaced by a new nozzle to be ground.

It is possible to invert the sequence of these two operations, i.e. to put aside the flat-grinding unit 21, 24 and to replace the completely ground nozzle by another nozzle to be completely ground and in the subsequent working step to advance the unit 21, 24 and to fiat-grind the new nozzle end 2.

Of course, the position of the three stations may be angularly shifted, by arranging station I in a lower position, in front of the service side.

FIGURE 11 shows diagrammatically a variation of the above-described grinding machine, according to which, as supporting member for the workpiece spindles a horizontal stepwise advancing disc 108 is rotatably mounted upon a shaft or axle 53 and upon which disc are mounted four substantially radial workpiece spindles 7 provided with outwardly arranged chucks.

To said four spindles 7 correspond four stations I, II, III and IV, the first three stations being working stations in which the end flattening and the internal grindings are effected ad the fourth being the nozzle-chucking and removing station.

Of course, the invention is not limited to the above-disclosed embodiments, but may be modified within the scope of the invention as defined in the appended claims.

I claim:

1. A multiple spindle grinder for diesel engine fuel nozzles, said grinder comprising a support, means for reciprocably moving said support, three parallel workpiece spindles, a rotatable disc on said support carrying said spindles, said spindles being connected to said disc along a circle at equal angular intervals, means for rotating said disc and said spindles therewith, stepwise, through three successive working stations, a grinding device at each staiton, one being an external flat-grinding device with a grinding disc for grinding the external flat end surface of a fuel nozzle, the second being an internal conical grinding device with a conical grinding surface for grinding the internal conical needle seat of the nozzles, the third being an internal cylindrical grinding device with a cylindrical grinding surface for grinding the internal cylindrical needle guiding surface, means supporting the flat grinding device at the first working station for movement between an operative position and an inoperative position, said means for reciprocally moving the support being capable of producing two advancing and withdrawing movements of the support and spindles to and from the grinding devices for each rotation step of the disc, and means for moving the flat grinding device to its inoperative position after each second advance movement of the support to enable removal of a finished ground nozzle at the first working station.

2. A grinder as claimed in claim 1 comprising dressing means at each station for dressing the grinding device thereat, means for moving the dressing means at the second and third stations conjointly to their associated grinding devices.

3. A grinder as claimed in claim 2 comprising means supporting the dressing means at the first station at a position to dress the grinding device thereat when it is in its inoperative position.

4. A grinder as claimed in claim 1 wherein said grinding device at said first station is arranged above the grinding devices at said second and third stations, the latter being disposed laterally of the grinding device at the first station and at the same level.

5. A grinder as claimed in claim 4, wherein said means References Cited which supports the grinding device at the first station is UNITED STATES PATENTS a transverse sllde for said first grlnding device.

6. A grinder as claimed in claim 1 comprising means 1,708,575 4/1929 Hohnhorstsupporting the grinding device at the second station for 5 1,837,319 12/1931 Fraser 51' 105 axial movement towards and away from said disc and 1,881,244 10/1932 Raule 51 '53 for angular movement about an axis perpendicular to the 2,423,367 7/1947 Bqlender 51 1O5 2,442,683 6/1948 Green 5150 axis of rotation of said disc.

7. A grinder as claimed in claim 6 comprising means ANDREW R, JUHASZ, Primary Examiner.

supporting the grinding device at the third station for 10 WEIDENFELD Assistant Examiner axial movement towards and away from said disc, and

for adjustable displacement along an axis which is inclined with respect to the axis of rotation of said disc. 515, 108, 134 

